[Buildroot] [RFC PATCH v3 00/10] Make the SDK relocatable

[Arnout Vandecappelle]

On 27-06-17 12:54, Wolfgang Grandegger wrote:
> Hello,
> 
> Am 21.06.2017 um 23:06 schrieb Arnout Vandecappelle:
>>
>>
>> On 21-06-17 23:03, Arnout Vandecappelle wrote:
>>>   Preferably as an instrumentation hook, because:
>>> - it speeds things up dramatically if you do 'make foo-rebuild';
>>> - things are still correct if you interrupt the build in the middle;
>>> - it makes no difference if you do a rebuild (if patchelf is done at the end,
>>> and then you rebuild a package, the RPATH in the libs you link with is different
>>> than the first time you built it).
>>
>>   Note, however, that doing it as an instrumentation hook could be a pretty
>> dramatic rewrite of your series, so if you don't feel up to it, I'm ok with
>> committing the current approach to begin with.
> 
> I just sent out v4 of my patch series doing the sanitation at the end of the
> build. Yes, using GLOBAL_INSTRUMENTATION_HOOKS would requires further
> modification to the framework. But also "check-bin-arch" and "check-host-rpath"
> does a lot of useless scanning for ELF files.
> Therefore it would make sense to use this mechanism to create a list of ELF
> files similar to the hook "step_pkg_size" (creating packages-file-list.txt),
> either per installation step or even better per package:
> 
>   build/target-packages-elf-files.txt
>   build/staging-packages-elf-files.txt
>   build/host-packages-elf-files.txt
> 
> or (per package)
> 
>   build/elf-file-list/<host|staging|target>-<package>-elf-files.txt

 I definitely like the per-package file list, because it smoothly scales to
per-package-staging. Ideally then the packages-file-list.txt should also be
split into a separate list per package. From there it's a small step to have an
elf-file list as well.

 Since it's anyway per-package, I'd put it directly in the package build
directory, e.g. $(@D)/.<host|staging|target>-files.txt and
$(@D)/.<host|staging|target>-elf-files.txt.

 But as I understand it, your proposal is to commit your series as is, with the
scanning done only in the finalize step, and refactor it with elf files lists later?


> If we do not need the per package list lateron, we could create it
> temporarily, call "fix-rpath" to do the sanitation and delete it afterwards. Or,
> even simpler, fix-rpath could work on ".br_filelist_before" and
> ".br_filelist_after" directly... that seems not too difficult to implement. What
> do you think?

 The latter was actually what I had in mind: refactor the step_pkg_size_end to
save the output of comm in a temporary file, and use that file to call the
fix-rpath script. That temporary file is basically $(@D)/.target-files.txt.


 Regards,
 Arnout

-- 
Arnout Vandecappelle                          arnout at mind be
Senior Embedded Software Architect            +32-16-286500
Essensium/Mind                                http://www.mind.be
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